6a024f1bfd
Add the new flag XE_BO_NEEDS_CPU_ACCESS, to force allocating in the mappable part of vram. If no flag is specified we do a topdown allocation, to limit the chances of stealing the precious mappable part, if we don't need it. If this is a full-bar system, then this all gets nooped. For kernel users, it looks like xe_bo_create_pin_map() is the central place which users should call if they want CPU access to the object, so add the flag there. We still need to plumb this through for userspace allocations. Also it looks like page-tables are using pin_map(), which is less than ideal. If we can already use the GPU to do page-table management, then maybe we should just force that for small-bar. Signed-off-by: Matthew Auld <matthew.auld@intel.com> Cc: Gwan-gyeong Mun <gwan-gyeong.mun@intel.com> Cc: Thomas Hellström <thomas.hellstrom@linux.intel.com> Cc: Lucas De Marchi <lucas.demarchi@intel.com> Reviewed-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com> Reviewed-by: Gwan-gyeong Mun <gwan-gyeong.mun@intel.com> Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.